4179181 Original Excavator Hydraulic Compres Spring for Hitachi ZX200-5A

Part number 4179181 is the original hydraulic compression spring officially designated by Hitachi Construction Machinery. This component is a key elastic element used in hydraulic systems to provide reset force or maintain set pressure. Mainly designed for Hitachi ZX200-5A medium-sized hydraulic excavator. Meanwhile, based on the high versatility of Hitachi excavator platform, this spring is highly likely to be suitable for 20 ton models such as ZX200-3, ZX200-5B, ZAX200 in the same series, as well as other Hitachi medium-sized excavators with similar hydraulic principles. As an original precision accessory, its size, stiffness (k value), and fatigue life are precisely matched with the corresponding valve body or mechanism

This product is a cylindrical spiral compression spring, which is an indispensable force control component in hydraulic systems. It is made of high-strength alloy spring steel (such as SUP10) through precision rolling, heat treatment (quenching+tempering), and surface treatment (such as phosphating or galvanizing), with excellent fatigue strength, high elasticity, and good anti relaxation performance. The steel wire diameter, pitch diameter, free height, total number of turns, end structure (and tightly ground flat) and other parameters of the spring have been accurately calculated and tested to ensure stable and linear elastic force within the specified compression stroke. In hydraulic systems, it is usually installed in the valve core return chamber of multi way valves, the pressure regulating chamber of relief valves or pressure reducing valves, and pilot control valves. Its core function is to ensure that the valve core is reset in a timely manner, maintain system back pressure or set a safe pressure value. It is the core basic component to ensure the accuracy of hydraulic action and system safety.

Inspection and diagnosis: In daily maintenance, the hydraulic system status should be checked in conjunction with the inspection. If the valve resets slowly, the action is not in place, the system pressure cannot be established or fluctuates abnormally, after excluding oil contamination and valve core jamming factors, it is necessary to suspect whether the spring has fatigue failure, permanent deformation (plastic deformation) or fracture. Disassembly inspection: During maintenance, carefully remove the spring after fully releasing the system pressure, check for rust and cracks on its surface, measure its free height to ensure it is within the tolerance range, and press it with your hand to feel if its elasticity is significantly reduced.